1. Field of the Invention
This invention relates generally to electronic components and, more particularly, to a facility for testing the electronic components under severe environmental conditions.
2. Description of the Related Art
A wide variety of applications for electronic components exists in which the components will be subjected to extreme ambient environmental conditions. Under these extreme environmental conditions, there is a greater likelihood of either unacceptable deterioration of performance or failure of the component. An important example is the use of electronic components for military applications in which extremes of environment can be anticipated. To minimize the impact of adverse environmental conditions, the performance parameters of the electronic components can be specified over a wide range of ambient temperature conditions. In order to insure that the components perform at these extreme environmental conditions, it is necessary to verify the component characteristics under the conditions of maximum environmental severity. Having tested the operational characteristics of a component under the severest expected conditions, this component can safely be designed into circuits without risk that the required characteristics will not be met under anticipated environmental conditions.
In the past, the testing of electronic components under these simulated conditions have typically been accomplished by attaching the electronic component to a suitable experimental testing circuit and cycling the component through the severest conditions. The components are then tested under those severest conditions to determine whether the performance parameters meet the predetermined requirement for the components. This testing procedure suffers from the necessity of placing a new component in the testing circuit at the end of each testing cycle and to recycle the environment of the new component. Such a procedure clearly does not lend itself to automated testing or to the testing of large numbers of components. To expedite speed the process and to render the process more susceptible to automation, a plurality of components and therefore a plurality of testing circuits can be exposed to the severe environmental conditions simultaneously. This testing procedure suffers from the requirement for a plurality of testing circuits to test the electronic components. In addition, when the testing requirements are altered, a multiplicity of new testing circuit configurations must be implemented. Furthermore, the test circuits themselves can be subjected to the severe environment condition. Finally, putting a large number of units to be tested into an environmental chamber using wire connections to a test apparatus precludes many dynamic tests due to the reactances in the long coupling wire.
A need has therefore been felt for an environmental testing facility for electronic components that can cycle a multiplicity of electronic components through severe environmental conditions and yet be suitable for automated execution of the testing procedures.